United States
Environmental Protection
Agency
Industrial Environmental Research EPA 600 '2-79-210)
Laboratory December 1979
Cincinnati OH 45268
Haaaarch and Development
Status
Assessment of
Toxic Chemicals
Phosphates
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-210J
December 1979
STATUS ASSESSMENT OF TOXIC CHEMICALS:
PHOSPHATES
by
J. C. Ochsner
T. R. Blackwood
Monsanto Research Corporation
Dayton, Ohio 45407
Contract No. 68-03-2550
Project Officer
David L. Becker
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory - Cincinnati, U.S. Environmental Protection
Agency, and approved for publication. Approval does not signify
that the contents necessarily reflect the views and policies of
the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or
recommendation for use.
11
-------
FOREWORD
When energy and material resources are extracted, processed,
converted, and used, the related pollutional impacts on our
environment and even on our health often require that new and
increasingly more efficient pollution control methods be used.
The Industrial Environmental Research Laboratory - Cincinnati
(lERL-Ci) assists in developing and demonstrating new and im-
proved methodologies that will meet these needs both efficiently
and economically.
This report contains a status assessment of the air emis-
sions, water pollution, health effects, and environmental signi-
ficance of cadmium. This study was conducted to provide a better
understanding of the distribution and characteristics of this
pollutant. Further information on this subject may be obtained
from the Organic Chemicals and Products Branch, Industrial
Pollution Control Division.
Status assessment reports are used by lERL-Ci to communicate
the readily available information on selected substances to
government, industry, and persons having specific needs and
interests. These reports are based primarily on data from open
literature sources, including government reports. They are indi-
cative rather than exhaustive.
David 6. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
111
-------
ABSTRACT
Large sources of phosphate, which result from the widespread use
of detergents from human wastes, and from surface water runoff
from phosphate fertilized acreage, can cause accelerated eutro-
phication of freshwater aquatic systems. Detergents have been
found to account for 50% to 70% of phosphate in domestic waste-
water, while human wastes account for the other 30% to 50%. An
estimated 1% to 5% of the phosphate applied as fertilizer reaches
surface water through runoff and percolation. This amounts to
about 46,000 metric tons to 230,000 metric tons (P2C>5 content)
of phosphate fertilizer per year. Municipal point sources
dominate phosphate loading in the Northeast, while agricultural
runoff dominates in the Southeast, Midwest, and West. Phosphate
control technology encompasses biological, chemical, chemical-
physical and physical techniques. Although a Federal phosphate
criterion has not been established, the EPA is currently consid-
ering the problem. To control accelerated eutrophication, total
phosphate phosphorus should not exceed 0.05 g/m3 in any stream
entering a lake or reservoir, or 0.025 g/m3 within the lake or
reservoir; the goal in other flowing streams is 0.1 g/m3. At
this time, 16 states have adopted effluent standards, with con-
centration limits ranging from 0.1 g/m3 to 2.0 g/m3 for total
phosphorus.
Areas in which additional study is recommended are: 1) a better
definition of where accelerated eutrophication is a problem and
what the sources of the problem are; 2) in areas of accelerated
eutrophication, the effectiveness of short-range control methods
such as phosphate detergent bans, plant cutting and harvesting,
or chemical application should be determined; 3) effect of
methods to control agricultural runoff in areas where accelera-
ted eutrophication is a problem; 4) a better understanding of
nutrient runoff into flowing streams and their environmental
fate; and 5) a cost/benefit analysis of phosphate detergent bans
versus clean-up of municipal wastewater.
This report was submitted in partial fulfillment of Contract
68-03-2550 by Monsanto Research Corporation under the sponsorship
of the U.S. Environmental Protection Agency. This report covers
the period November 1, 1977 to December 31, 1977. The work was
completed as of January 20, 1978.
IV
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CONTENTS
Foreword iii
Abstract iv
Conversion Factors and Metric Prefixes vi
Acknowledgement vii
1. Introduction 1
2. Summary 2
3. Source Description 5
Background 5
Sources of phosphates 5
4. Environmental Significance 9
5. Control Technology 12
Biological removal 12
Chemical application 12
Chemical-physical removal 13
Physical methods 13
6. Regulatory Action 16
State regulatory agencies 16
State standards 16
Future regulatory considerations 17
References 19
Glossary 21
v
-------
CONVERSION FACTORS AND METRIC PREFIXES*
To convert from
Centigrade (°C)
Meter (m)
Meter2 (m2)
Meter 3
Metric
Metric
Metric
(m3)
ton
ton
ton
Pascal (Pa)
Total phosphate
CONVERSION FACTORS
To
Fahrenheit (°F)
Foot
Foot2
Foot3
Pound-mass
Kilogram
Ton (short, 2,000 pound-
mass)
Pound-force/inch2 (psi)
Total phosphorus as
elemental phosphate
Multiply by
2.205
3.281
1.076 x 101
3.531 x 101
2.205 x 103
1.000 x 103
1.585 x I0~k
1.450 x 10~k
0-33
METRIC PREFIXES
Prefix Symbol Multiplication factor
Kilo
Mega
Micro
Milli
k
M
y
m
103
106
10~6
10~3
Example
1 kPa = 1 x 103 pascals
1 MJ = 1 x 106 joules
1 g = 1 x 10~6 gram
1 mg = 1 x 10~3 gram
Standard for Metric Practice. ANSI/ASTM Designation:
E 380-76e, IEEE Std 268-1976, American Society for Testing and
Materials, Philadelphia, Pennsylvania, February 1976. 37 pp.
VI
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ACKNOWLEDGEMENT
This report was assembled for EPA by Monsanto Research Corpora-
tion, Dayton, OH. Mr. D. L. Becker served as EPA Project Officer,
and Dr. C. E. Frank, EPA Consultant, was principal advisor and
reviewer.
vx i
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SECTION 1
INTRODUCTION
Phosphates, resulting from human wastes, the widespread use of
detergents, surface water runoff, and phosphate fertilized
acreage, can cause accelerated eutrophication of freshwater
aquatic systems. This generates unsightly aquatic plant growth
that interferes with the usage of the water.
To organize a management system for controlling phosphates, in-
formation must be obtained on emission sources, environmental
effects, control technology, and present status of phosphates
control.
The purpose of this report is to briefly present the information
required for a phosphates management system.
-------
SECTION 2
SUMMARY
Phosphorus is widely distributed in natural water and wastewater
in three forms: organically bound phosphate, inorganic condensed
phosphate, and orthophosphate. Orthophosphate is the simplest
and most reactive form for chemical and biological removal.
Phosphate is necessary for the growth of many organisms in na-
tural waters, but excessive amounts result in overfertilization.
Standing crops of aquatic plants sufficiently increase to inter-
fere with water uses and become nuisances to man. This phenomena
accelerates the process of eutrophication, which is the natural
process of aging in a lake caused by biological and chemical
enrichment.
Phosphates originate from point and nonpoint sources. Point
sources include discharges from municipal and industrial activi-
ties, while nonpoint sources mainly involve land runoff.
Domestic wastewater dominates the point source category in total
phosphorus. Detergents have been found to account for 50% to 70%
of this effluent.
Phosphorus contained in land runoff results largely from the
addition of fertilizer to agricultural land. An estimated 1% to
5% of the phosphorus applied as fertilizer reaches surface water
through runoff and percolation. This amounts to 46,000 metric
tons to 230,000 metric tons (P2C>5 content) of phosphate fertili-
zer per year.
A conclusion of the National Commission on Water Quality is that
municipal discharges, urban storm runoff, and combined storm and
sewer overflows account for many of the nutrient loadings in the
Northeast; and that land runoff is a large contributor in the
agricultural areas of the Southeast, Midwest, and West.
A desired goal for preventing plant nuisances in streams or other
flowing waters not discharging directly to lakes or impoundments
is 0.1 g/m3 total phosphate expressed as elemental phosphorus
(TPP). Most relatively uncontaminated lake districts have sur-
face waters that contain from 0.01 g/m3 to 0.03 g/m3 TPP.
-------
Phosphorus control technology encompasses several technologies.
Biological, chemical, chemical-physical, and physical techniques
have successfully removed phosphorus from wastewater or have been
directly applied to reducing aquatic plant growth.
In states which have wastewater effluent phosphorus standards,
most concentration limits range from 0.1 g/m3 to 2.0 g/m3 TPP,
with many established at 1.0 g/m3. Table 1 presents a brief
summary of the information contained in this report.
Recommended areas for further study are:
• Better definition of where accelerated eutrophication is
a problem and what the sources of the problem are.
• In areas where accelerated eutrophication has been defined
as a problem, what is the effectiveness of short-range
control methods such as phosphate detergent bans, plant
cutting and harvesting, or chemical application.
• Effect of methods to control agricultural runoff in areas
where accelerated eutrophication is a problem.
• Better understanding of nutrient runoff into flowing
streams and their fate in the environment.
• Cost/benefit analysis of phosphate detergent bans versus
clean-up of municipal wastewater.
-------
TABLE 1. PHOSPHATES
Source
Extent of problem
Control technology
Regulatory action
Point:
Industrial
Municipal:
Treatment facility
Urban runoff
Biological and chemical-
physical methods.
Nonpoint:
Land runoff
Precipitation
Groundwater
Wildlife wastes
Sediments
Minor contributor.
Maj or contributor in
the Northeast.
Detergents generally
account for most
phosphate in domestic
wastewaters (50% to
• 70%), human wastes
account for the remain
der (30% to 50%) .
Agricultural land run- Direct application of
Each state has at least
one organization respon-
sible for water pollution
prevention. In the
states which have efflu-
ent phosphorus standards,
most concentration limits
range from 0.1 g/m3 to
2.0 g/m3 TPP (total phos-
phate expressed as ele-
mental phosphorus).
off is the major con-
tributor. It is also
the dominate contribu-
tor to phosphate load-
ing in the Midwest,
Southwest, and West.
chemical, physical,
and biological means
of the reduction of
aquatic plants.
-------
SECTION 3
SOURCE DESCRIPTION
BACKGROUND
Three forms of phosphate phosphorus are widely distributed in
natural water and wastewater: organically bound phosphate,
inorganic condensed phosphate, and orthophosphate. Organically
bound phosphate, the least abundant of the three forms, is found
in ester and anhydride configurations. These configurations are
parts of proteins, phospholipids, nucleic acids, and bacterial
cell mass. Organic phosphate is broken down by enzyme action
and does not precipitate with metallic salts. Inorganic con-
densed phosphates contain two or more phosphorus atoms in a ring
or chain structure. Detergents contribute most of this form as
poly- and pyrophosphates. The remainder comes from the metabolic
breakdown of proteins in human waste. All the inorganic forms
slowly hydrolyze in an aqueous environment to the ortho form.
Orthophosphate is the simplest and most reactive form for chem-
ical and biological removal. Orthophosphate equilibria include
H3P0lt, H2PO^, HPO^2, and POiJ3, in a pH-determined system.
Some phosphate is necessary for the growth of many organisms in
natural waters, but excessive amounts result in overfertiliza-
tion. During the past 30 yr, standing crops of aquatic plants
have increased enough to interfere with water uses to become
nuisances to man. Such phenomena are associated with accelerated
eutrophication, or aging of lake waters. Phosphates are not the
sole cause of eutrophication, but substantial evidence indicates
that it is the limiting factor for plant growth. An increase in
phosphate permits use of existing nutrients.
SOURCES OF PHOSPHATES
Control of accelerated .eutrophication often involves reduction
or elimination of nutrient loadings. Before a phosphate loading
can be controlled, sources of this nutrient must be identified.
These may be point sources, such as the effluent of a municipal
or industrial wastewater treatment facility, or nonpoint sources,
aNote—Phosphorus and phosphate are used interchangeably in this
report and should not be confused with phosphorus in the ele-
mental form.
-------
such as precipitation, groundwater, wildlife wastes, land runoff,
and resuspension of sediments in water.
Industrial Wastewater
An unknown amount of industrially produced phosphorus wastes
exists in waste treatment plant influent. However, the very low
proportion of industrial phosphorus discharge (4% of the total
amount of phosphorus wastes generated) measured during a govern-
ment study on Lake Erie, suggests that industry is a very minor
contributor (1).
Municipal Wastewater
Domestic wastewater normally contains a substantial concentration
of phosphorus resulting from human activities. Human wastes such
as feces, urine, and waste food disposal account for about 30% to
50% of the phosphorus in domestic wastewater (2). Detergents
which contain phosphate builders and which are principally used
for laundering clothes account for the remaining phosphorus,
about 50% to 70%.
A study conducted during a phosphorus detergent ban in New York,
found a 55.7% reduction in phosphorus loading at a domestic
wastewater treatment facility (3). Other sources, such as adding
sodium hexametaphosphate or other phosphorus compounds to water
supplies for corrosion and scale control can account for 2% to
20% of the total phosphorus present in wastewater (2).
Nonpoint Sources
Even if all phosphates were removed from sewage effluents, less
controllable nonpoint sources would still be a major problem.
Unless particulate matter is picked up from the atmosphere, nat-
ural precipitation contains almost no phosphorus, and groundwater
has been reported at less than 0-2 g/m3 total phosphate reported
as elemental phosphorus (3). Direct input of wild animal wastes
is usually a minor source of phosphorus unless a lake supports
an unusually large population of wildlife.
(1) Willis, I. G. The Balance Between Waste Treatment and Waste
Discharge in the U.S., 1957-2000. Journal of the Water
Pollution Control Federation, 46(3):438-457, 1974.
(2) Process Design Manual for Phosphorus Removal. EPA-625/1-76-
001-a, U.S. Environmental Protection Agency, Washington,
D.C., April 1976. 260 pp.
(3) Morse, J. W., K. J. Little, and U. A. Garrison. Eutrophi-
cation in Vermont. Water Quality Surveillance Series,
Report No. 3 (PB 267 844), Department of Water Resources,
Agency of Environmental Conservation, Montpelier, Vermont,
1967, 69 pp.
-------
Drainage from agricultural land produces large amounts of phos-
phate. Phosphorus contained in agricultural land runoff results
largely from adding fertilizers to the soil to boost crop pro-
duction (1). In Wisconsin it was found that runoff contributed
38 kg of phosphorus per square kilometer per year (4). Phos-
phates entering soil are quickly bound to soil particles;
therefore, most of the phosphorus carried into lakes or streams
by land runoff is actually attached to soil particles rather
than dissolved in runoff water. The phosphorus content of runoff
water is dependent upon the amount of erosion occurring in a
watershed. The steeper the slope the greater is the contribu-
tion. The following values were calculated from figures for the
annual contribution from arable land in Wisconsin (4):
Slope Phosphorus, kg/km2 '
20° 160
8° 45
It has been suggested that nearly all the phosphate reaching
streams in agricultural areas does so through bank erosion (4).
Indications are that nutrients soon enter plants and are then
recycled fairly fast in the stream. However, phosphate concen-
trations have also been found to increase in the downstream
direction (4). The amounts of nutrients available and the possi-
bility that they may actually control the growth of primary
producers in streams merits further study.
Cropland or pastureland runoff contains more phosphorus than
does forest runoff because of applications of fertilizer in the
form of manure or commercial preparations. In addition, because
the forest floor may be completely covered with vegetation or
litter, little erosion occurs. A recent study found a mean
total phosphorus content 10 times greater in water from agricul-
tural land than from the forest (5) . As more fertilizer is
applied, more phosphorus is bound to the soil particles later
carried away in runoff. Normally, an estimated 1% to 5% of
phosphorus applied as fertilizer reaches surface waters through
runoff and percolation (3).
(4) Hynes, H. B. N. The Ecology of Running Waters. Liverpool
Press, Liverpool, England, 1970. 450 pp.
(5) Omernik, J. M. The Influences of Land Use on Stream Nutri-
ent Levels. EPA-600/3-76-014, U.S. Environmental Protection
Agency, Washington, D.C., January 1976. 117 pp.
-------
Using the 1974 consumption of phosphate fertilizers, 4.6 x 106
metric tons (PaOs content) (6), results in 46,000 metric tons to
230,000 metric tons of phosphate fertilizer reaching surface
waters per year.
The role of sediments in releasing phosphates into lakewater is
controversial and not well defined; however, it is believed to
be a source of phosphate eutrophication.
(6) Commercial Fertilizers. Crop Reporting Board, U.S. Depart-
ment of Agriculture, Washington, D.C., 1 November 1974.
11 pp.
8
-------
SECTION 4
ENVIRONMENTAL SIGNIFICANCE
Several investigators assert that eliminating .phosphates in waste
streams (point sources) is essential to controlling accelerated
eutrophication (7-13). One study determined that 72% of the sol-
uble phosphorus entering one eutrpphic lake came from wastewater
discharges (14). Other studies have shown that wastewater
accounts for 57% to 94% of the input phosphorus to eutrophic
lakes (15, 16).
(7) Stumm, W. Man's Acceleration of Hygrogeochemical Cycling
of Inland and Coastal Water. Water Pollution Control,
74(2):124-133, 1975.
(8) Bradshaw, J. S., R. B. Sun, D. A. Shite, J. R. Barton, D. K.
Fuhriman, E. L. Loveridge, and D. R. Pratt. Chemical Re-
sponse of Utah Lake to Nutrient Flow. Journal of the Water
Pollution Control Federation, 45 (5):880-888, 1973
(9) Lin, S. S. and D. A. Carlson. Phosphorus Removal by the
Addition of Aluminum (III) to the Activated Sludge Process.
Journal of the Water Pollution Control Federation,
47(7):1978, 1976.
(10) Balmer, P., and 0. F. Frederiksen. A Pilot Plant Scale
Evaluation of Potential Precipitants in the Secondary
Precipitation Process. Water Research, 9:721-727, 1975.
(11) Huang, V. H., J. Mase, and E. G. Fruh. Nutrient Studies in
Texas Impoundments. Journal of the Water Pollution Control
Federation, 45(1):105-118, 1973.
(12) Federal Register, 38 (206) .-29646, 1973.
(13) Toerien, D. F. South African Eutrophication Problems. A
Perspective. Water Pollution Control, 74 (2):134-142, 1975.
(14) Hething, L. J., and R. M. Sykes. Sources of Nutrients in
Cohandarago Lake. Journal of the Water Pollution Control
Federation, 45 (1):145-156, 1973.
(15) MacKenthium, K. M., L. E. Leup, and R. K. Stewart. Nutri-
ents and Algae in Lake Sebasticook, Maine. Journal of the
Water Pollution Control Federation, 49(2):R72-R81, 1968.
(16) Report to the International Joint Commission on the Pollu-
tion of Lake Erie, Lake Ontario, and the International
(continued)
9
-------
A conclusion of the National Commission on Water Quality is that
municipal discharges, urban storm runoff, and combined storm and
sewer overflows account for much of the nutrient loadings in the
Northeast; and that land runoff (nonpoint sources) is a large
contributor in the agricultural areas of the Southeast, Midwest,
and West.
A study which was performed for the National Commission on Water
Quality indicated the relative importance of major effluent-
generating activities (17). These activities included point
sources, municipal and industrial activities, and agricultural
nonpoint sources and urban nonirrigated agricultural runoff.
Phosphate was studied for municipal and agricultural activities;
the results—presented in Table 2 and in Figure 1—show that
agriculture dominates in five geographical regions using 1973
estimates (17). These regions in Figure 1 (C, D, E, F, and G)
include areas of the Southeast, Midwest, and West.
TABLE 2. ESTIMATES OF 1973 PHOSPHATE GENERATION, DISCHARGE,
AND DISCHARGE AFTER CONTROL FOR SELECT SOURCES (17)
10 a metric tons total phosphorus as P
Geographic
regions*
A
B
C
D
E
F
G
H
I
J
K
L
M
1973
Generation
15
58
42
70
12
17
25
1
7
0.9
5
12
20
1973
Discharge
13
47
31
41
10
13
18
0.9
6
0.'9
4
10
17
Secondary
treatment
10
39
27
40
8
12
17
0.9
5
0.5
4
9
14
Best practicable
wastewater treatment Agriculture,
technology
9
29
16
18
7
10
5
0.5
5
0.5
2
7
5
Runoff
4
63
134
189
235
428
240
1
36
16
0.9
2
4
Control
2
31
72
92
119
217
125
0.9
20
7
0.5
0.9
2
National
total
285
212
186
114
1,353
689
See Figure 1-.
1 metric ton equals 10^ grams; conversion factors and metric system prefixes are presented in the
prefatory material.
(continued)
Section of the St. Lawrence River, Volume 1. Queen's
Printer, Ottawa, Ontario, Canada, 1969.
(17) Pechan, E. J. Summary Report on The National Residuals
Discharge Inventory. National Commission on Water Quality,
National Research Council, Washington, D.C., March 1976.
50 pp.
10
-------
Figure 1. Geographic regions which were selected for
estimates of phosphate discharge (15).
11
-------
SECTION 5
CONTROL TECHNOLOGY
Phosphorus removal encompasses several technologies; biological,
chemical, chemical-physical, and physical techniques have suc-
cessfully removed phosphorus from wastewater or have been di-
rectly applied to reducing aquatic plant growth.
BIOLOGICAL REMOVAL
Microorganisms remove dissolved orthophosphate from wastewater
in the process of cell synthesis and respiration. The overall
amount of phosphorus removed by a biological unit is determined
by both the cell wasting rate and the maximum amount of phospho-
rus that may be incorporated into the cell mass. Chemical pre-
cipitation may also occur but usually is not the primary removal
mechanism in a biological system.
In conventional flow schemes a trickling filter system utilizing
microorganisms can be expected to remove 20% to 30% phosphorus,
an activated sludge system can remove 30% to 50% phosphorus (18).
The low removal is due to the low carbon to phosphorus ratio
(less than 100:1) usually encountered in sewage. Since carbon to
phosphorus ratios required for cell growth must usually be 100:1,
a nutritionally unbalanced situation exists with phosphorus in
excess and carbon the limiting nutrient (18).
Biological methods have also been suggested for direct control of
aquatic plants. These involve introducing fish, mammal, fowl,
or snail populations which would feed on the plants to an area.
However, these have limited applicability and are not widely
used.
CHEMICAL APPLICATION
Chemical methods of controlling algae and aquatic plants are
utilized throughout the United States. Chemicals used for aqua-
tic plant control include copper sulfate, diquat, endothall,
dalapon, dichlobenil, diuron, 2,4-dichlorophenoxyacetic acid,
(18) Ryczak, R. S., and R. D. Miller. A Review of Phosphorus
Removal Technology, Technical Report 7706 (ADA 040 802),
U.S. Army Medical Research & Development Command,
Washington, D.C., May 1977. 66 pp.
12
-------
2,4,5-trichlorophenoxy acetic acid, and 2,4,5-trichlorophenoxy
propionic acid. The use of chemicals is advantageous because
they are easy to apply, they require minimal equipment, and they
usually kill or reduce nuisance growths within a week. The dis-
advantages of chemical application are numerous. Application
will not stop eutrophication, it will only retard it. Repeat
applications are required for continuous control. In addition,
long-term residual effects of introducing a toxic chemical into
the aquatic environment may be worse than the effect of the
phosphate, especially with nonbiodegradable products which can
accumulate in aquatic organisms or sediments.
CHEMICAL-PHYSICAL REMOVAL
Phosphorus removal can be successfully accomplished by chemical-
physical processes. Physical-chemical processes include pre-
cipitation, coagulation, flocculation, sedimentation, filtration,
and flotation. Several of these processes are combined in series
to effect phosphorus removal to desired levels. The phosphorus
must first be insolubilized1, then the solid must be separated
from the liquid and disposed so that it will not readily reenter
the environment. Physical-chemical process combinations are able
to remove, orthophosphate and condensed phosphate forms from
widely varying waste streams.
PHYSICAL METHODS
Physical methods of controlling algae and aquatic plants are
often proposed where chemical or biological control would be
ineffective or harmful.
Physical control methods include aeration, dilution with nutri-
ent-poor water, nutrient diversion, drawdowns (reducing water
level), dredging, aquatic plant cutting, and aquatic plant har-
vesting. Although physical methods usually require more time
and labor, no toxic substances or alien species are introduced
to the aquatic environment. Some disadvantages are that control
is only temporary or impractical (i.e., dilution which requires
large quantities of nutrient-poor water).
Erosion control is also a method of managing phosphate loadings.
Poor farming practices can increase agricultural loss of phos-
phates. If manure is spread on frozen land which slopes down
to a body of water or on land which floods in the spring, most
of the phosphorus applied is flushed into streams during spring
thaws. Overgrazing commonly causes soil erosion while corn or
other row crops leave the soil more susceptible to erosion than
untilled land. When livestock is confined to a small area,
surface runoff from the resultant manure is high in phosphorus.
Farm ponds should be fenced to limit livestock access and conse-
quent bank erosion (3).
13
-------
The results of a nationwide survey which asked each state to
describe its problems and recommended measures for controlling
aquatic plant growth are presented in Table 3 (3).
Of the 39 responding states, 9 reported no serious plant and
algae problems or no statewide control programs. Only 5 of the
31 states reporting aquatic algae problems have well-developed
lake restoration programs. Of the seven states reporting biolog-
ical control methods, most are only in the investigative stages.
Finally, 12 states reported using physical control measures such
as pulling up nuisance growth or water level manipulation.
14
-------
TABLE 3. RESULTS OF NATIONWIDE SURVEY ON WEED
AND ALGAE PROBLEMS AND SOLUTIONS (3).
Chemicals
,
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
0)
•P
id
•H
CO
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
rH
H
(0
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SECTION 6
REGULATORY ACTION
STATE REGULATORY AGENCIES
Each state has at least one organization reponsible for water pol-
lution prevention, control, and abatement activities. In about
one-half of the 50 states, this responsibility is divided between
two state agencies. Usually one of these is the state health
department and the other is an organization charged specifically
by statute with the conduct of the state's water pollution con-
trol program. Although there has been an intensification of
Federal activities in water pollution control over the past 20
yr, much of the responsibility for program operations rests with
the states. Invariably the appropriate state agencies should be
consulted in connection with the planning and conduct of water
pollution control programs at cities and other communities. The
U.S. Environmental Protection Agency regional office personnel
work closely with state agencies and can give advice regarding
proper state agency contacts.
STATE STANDARDS
As of June 1971, 16 states had adopted wastewater effluent phos-
phorus standards. In general, these standards have taken the
form of an effluent concentration limit or a requirement for a
specified percentage reduction in the phosphorus concentration
in the raw wastewater. In most cases, effluent concentration
limits range from 0.1 g/m3 to 2.0 g/m3 total phosphorus, with
many established at 1.0 g/m3. Percentage reduction requirements
range from 80% to 95% (2) .
It should be noted that neither an effluent nor a percentage-
reduction standard actually limits the phosphorus load in terms
of pounds of phosphorus discharged per day. Load (kilograms
per day.) is a direct function of both effluent phosphate concen-
tration and daily effluent volume. Assuming that the effluent
concentration standard is being met, an increase in the daily
flow of effluent will produce a proportionate increase in the
mass of phosphorus discharged daily to the receiving waters. If
the phosphorus load then becomes intolerable, adjustment down-
ward of the effluent concentration standard will be necessary.
Similarly, adjustment upward of a percentage-reduction standard
will be required if the phosphorus load becomes objectionable
16
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as a result of increased wastewater flow or increased phosphate
concentration in the raw wastewater or both (2) .
FUTURE REGULATORY CONSIDERATIONS
Although a total phosphorus as phosphate criterion to control
nuisance aquatic growths has not been presented, the following
rationale to support such a criterion is being considered by
EPA (19).
Total phosphate phosphorus concentrations in excess of 0.10 g/m3
total phosphate expressed as elemental phosphorus (TPP) may
interfere with coagulation in water treatment plants. When such
concentrations exceed 0.025 g/m3 at the time of the spring turn-
over on a volume-weighted basis in lakes or reservoirs, they may
occasionally stimulate excessive or nuisance growths of algae and
other aquatic plants. Algal growths impart undesirable tastes
and odors to water, interfere with water treatment, become aes-
thetically unpleasant, and alter the chemistry of the water supply.
They contribute to the phenomenon of cultural eutrophication.
To prevent the development of biological nuisances and to control
accelerated or cultural eutrophication, TPP should not exceed
0.05 g/m3 in any stream at the point where it enters any lake or
reservoir or 0.025 g/m3 within the lake or reservoir. A desired
goal for the prevention of plant nuisances in streams or other
flowing waters not discharging directly to lakes or impoundments
is 0.1 g/m3 TPP (18). Most relatively uncontaminated lake
districts are known to have surface waters that contain from
0.01 g/m3 to 0.3 g/m3 TPP (18)..
Another method of controlling the inflow of nutrients, particu-
larly phosphorus, into a lake is that of prescribing an annual
loading to the receiving water. Data in Table 4 suggests TPP
loadings in grams per square meter of surface area per year that
will represent critical levels for eutrophic conditions within
the receiving waterway for a particular water volume where the
mean depth of the lake in meters is divided by the hydraulic
detention time in years (19). The data present a range of load-
ing values that should result in oligotrophic lake water quality.
Regulations for feedlots and for phosphate manufacture are con-
tained in reference 20.
(19) Quality Criteria for Water. EPA-440/9-76-023, U.S. Environ-
mental Protection Agency, Washington, D.C., July 1976.
501 pp.
(20) Final Effluent Guidelines and Standards. EPA-330/1-77-007,
U S Environmental Protection Agency, National Environmental
Information Center, Denver, Colorado, June 1977. 128 pp.
17
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TABLE 4. PERMISSIBLE AND CRITICAL PHOSPHATE LOADING (19)
Mean depth hydraulic
detention time,
(m/yr)
Oligotrophic or
permissible
loading,
(g/m2-yr)
Eutrophic
or critical
loading,
(g/m2-yr)
0.5
1.0
2.5
5.0
7.5
10.0
25.0
50.0
75.0
100.0
0.07
0.10
0.16
0.22
0.27
0.32
0.50
0.71
0.87
1.00
0.14
0.20
0.32
0.45
0.55
0.63
00
41
1.73
2.00
1,
1,
18
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REFERENCES
1. Willis, I. G. The Balance Between Waste Treatment and Waste
Discharge in the U.S., 1957-2000. Journal of the Water Pol-
lution Control Federation, 46 (3) : 438-457, 1974.
2. Process Design Manual for Phosphorus Removal. EPA-625/1-76-
001-a, U.S. Environmental Protection Agency, Washington,
D.C., April 1976. 260 pp.
3. Morse, J. W. , K. J. Little, and U. A. Garrison. Eutrophi-
cation in Vermont. Water Quality Surveillance Series,
Report No. 3 (PB 267 844), Department of Water Resources,
Agency of Environmental Conservation, Montpelier, Vermont,
1975. 69 pp.
4. Hynes, H. B. N. The Ecology of Running Waters. Liverpool
Press, Liverpool, England, 1970. 450 pp.
5. Omernik, J. M. The Influence of Land Use on Stream Nutrient
Levels. EPA-600/3-76-014, U.S. Environmental Protection
Agency, Washington, D.C., January 1976. 117 pp.
6. Commercial Fertilizers. Crop Reporting Board, U.S. Depart-
ment of Agriculture, Washington, D. C. , 1 November 1974.
11 pp.
7. Stumm, W. Man's Acceleration of Hygrogeochemical Cycling of
Inland and Coastal Water. Water Pollution Control,
74(2) :124-133, 1975.
8. Bradshaw, J. S., R. B. Sun, D. A. White, J. R. Barton, D. K.
Fuhriman, E. L. Lover idge, and D. R. Pratt. Chemical Re-
sponse of Utah Lake to Nutrient Flow. Journal of the Water
Pollution Control Federation, 45 (5) : 880-888, 1973.
9. Lin, S. S. and D. A. Carlson. Phosphorus Removal by the
Addition of Aluminum (III) to the Activated Sludge Process.
Journal of the Water Pollution Control Federation,
47(7) :1978, 1975.
10. Balmer, P., and 0. F. Frederiksen. A Pilot Plant Scale
Evaluation of Potential Precipitants in the Secondary
Precipitation Process. Water Research, 9:721-727, 1975.
19
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11. Huang, V. H., J. Mase and E. G. Fruh. Nutrient Studies in
Texas Impoundments. Journal of the Water Pollution Control
Federation, 45 (1):105-118, 1973.
12. Federal Register, 38 (206):29646, 1973.
13. Toerien, D. F. South African Eutrophication Problems: A
Perspective. Water Pollution Control, 74 (2):134-142, 1975.
14. Hething, L. J., and R. M. Sykes. Sources of Nutrients in
Cohandarago Lake. Journal of the Water Pollution Control
Federation, 45 (1):145-156, 1973.
15. MacKenthium, K. M., L. E. Leup, and R. K. Stewart. Nutri-
ents and Algae in Lake Sebasticook, Maine. Journal of the
Water Pollution Control Federation, 49(2):R72-R81, 1968.
16. Report to the International Joint Commission on the Pollu-
tion of Lake Erie, Lake Ontario, and the International Sec-
tion of the St. Lawrence River, Volume 1. Queen's Printer,
Ottawa, Ontario, Canada, 1969.
17. Pechan, E. H. Summary Report on The National Residuals
Discharge Inventory. National Commission on Water Quality,
National Research Council, Washington, D-C., March 1976.
50 pp.
18. Ryczak, R. S-, and R. D. Miller. A Review of Phosphorus
Removal Technology, Technical Report 7706 (ADA 040 802),
U.S. Army Medical Research & Development Command,
Washington, D.C. May 1977. 66 pp.
19. Quality Criteria for Water. EPA-440/9-76-023, U.S. Envi-
ronmental Protection Agency, Washington, D.C., July 1976.
501 pp.
20. Final Effluent Guidelines and Standards. EPA-330/1-77-007,
U.S. Environmental Protection Agency, National Environmental
Information Center, Denver, Colorado, June 1977. 128 pp.
20
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GLOSSARY
aeration: Release of air under the water surface to ensure
oxygenation and mixing of a water body.
algae (alga): Simple plants, many microscopic, containing chlo-
rophyll. Most algae are aquatic and may produce a nuisance
when conditions are suitable for prolific growth.
aquatic plants: Plants growing in or on water.
cultural eutrophication: Accelerated eutrophication due to man's
impact on a water body; e.g., due to point sources of nut-
rients or agricultural runoff.
dilution: replacement of eutrophic lakewater by water lower in
nutrients; e.g., by flushing.
drawdown: Release of water from a dam structure causing the
water level to go down.
dredging: Removal of sediments from a lake or river bottom by
machine, such as suction or hydraulic dredges.
eutrophic: Process of aging in a lake caused by chemical or
biological enrichment.
loading: Quantity of a substance entering a water body over a
given time period.
limiting nutrient: Nutrient whose demand exceeds its supply such
that growth is restricted until more is available.
nonpoint sources: Nutrient sources which enter a water body at
numerous locations rather than at a single discharge.
nutrient: Chemical required for growth or maintenance by an
organism.
nutrient diversion: Diversion of high nutrient effluents into
another basin to bypass the threatened lake.
oligotrophic: Waters with a small supply of nutrients, unproduc-
tive. Little oxygen stratification.
21
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percolation: Penetration of water through soil.
phosphate: The ion PO^3, an important nutrient.
phospholipids: A class of complex phosphoric esterlipides that
are found in all living cells.
point source: A nutrient source which is discharged to a body of
water at a single location.
polyphosphate: A salt or ester of a polyphosphoric acid.
pyrophosphate: A salt or ester of pyrophosphoric acid—called
also diphosphate.
retention time: Average time that water is held in a basin;
e.g., the time needed to refill an emptied reservoir.
runoff: Portion of precipitation on the land that ultimately
reaches streams, especially water from rain or melted snow
that flows over the surface.
secondary treatment: Biological treatment of wastewater such as
trickling filters or activated sludge following mechanical
treatment. Bacteria consume the organic parts of the
wastes.
sediment: Matter that settles to the bottom of a body of water;
e.g., sand or silt from soil erosion, dead plant and animal
material.
watershed: Land area which drains to a particular body of water
or watercourse.
22
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TECHNICAL REPORT DATA
(f lease read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-79-210i
4. TITLE AND SUBTITLE
Status Assessment of Toxic
2.
Chemicals : Pho
7. AUTHOR(S)
T.R. Blackwood, J.C. Ochsner
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monsanto Research Corp
1515 Nichols Road
Dayton, Ohio 1+5U07
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Lab. -
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 1+5268
15. SUPPLEMENTARY NOTES
lERL-Ci project leader for
3. RECIPIENT'S ACCESSION-NO.
5. REPORT DATE
December 1979 issuing date
Spnatce g PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
1AB60^
11. CONTRACT/GRANT NO.
68-03-2550
13. TYPE OF REPORT AND PERIOD COVERED
Cinn, OH Task final 11/77 - 12/77
14. SPONSORING AGENCY CODE
EPA/600/12
this report is Dr. Charles Frank, 513-68^-^81
16. ABSTRACT
Uses, sources, and quantities of phosphates are discussed in this
report, with particular emphasis on the problem of fresh water
eutrophication. Recommended standards and current control
technologies are reviewed. Areas requiring further study are
identified.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
Phosphatases, Enzymes, Esterases, Hydro-
lases, Acid phosphatase, Alkaline Phos-
phatases, Phosphate deposits, Mineral
deposits, clastic rocks, evaporitic rocks,
igneous rocks , metamorphic rocks , sediment
rocks , phosphorus
13. DISTRIBUTION STATEMENT
Release to Public
b.lDENTIFIERS/OPEN ENDED TERMS
Phosphates, detergents,
fertilizers, wastewater
domestic wastewater
iry
19. SECURITY CLASS (This Report)
Unclassified
20. SECURITY CLASS (This page)
Unclassified
c. COSATI Field/Group
68D
21. NO. OF PAGES
31
22. PRICE
EPA Form 2220-1 (9-73)
23
ft U.S. GOVERNMENT WONTING OFFICE: 1980-657-146/5505
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